Collapse of Prefabricated Concrete Slab Houses

Prefabricated concrete slab houses are at risk of collapse, primarily due to the structural characteristics of the prefabricated panel joints, as detailed below:

Poor Integrity: Prefabricated concrete slab houses are constructed by joining multiple prefabricated panels, resulting in poor overall structural integrity. Under normal use, each panel shares the load. However, if any panel develops issues, such as cracks or fractures due to aging or external impacts, it alters the stress distribution on the other panels. This change can trigger a chain reaction, causing other panels to fail sequentially and ultimately leading to the risk of total collapse. This flaw is particularly evident during natural disasters like earthquakes. The vibrations generated by an earthquake can loosen the connections between panels, causing upper panels to fall and crush those below, layer by layer, ultimately burying people and objects within the building under rubble.

Weak Seismic Resistance: Many prefabricated panel buildings constructed in earlier years were designed to withstand seismic forces of only 6 degrees on the seismic intensity scale, whereas newly built residences typically require standards of 7 to 8 degrees. This means that during an earthquake, the joints between prefabricated panels are prone to cracking and misalignment. Due to the relatively weak connections between panels, the joints cannot effectively resist seismic forces under strong vibrations, leading to the entire floor slab detaching. Once a floor slab detaches, it not only damages the structural integrity of the building but also poses a severe threat to human life, significantly reducing escape time.

Limited Load-Bearing Capacity: The load-bearing capacity of prefabricated concrete slabs is limited. For example, the house collapse incident in Fengshou Community, Guanba Town, Zhong County, Chongqing, on April 11, 2024, occurred because the temporary load stacked on the second-floor slab exceeded its capacity, causing brittle fracture and collapse, ultimately resulting in 2 deaths and 3 injuries. This indicates that in practical use, if the load-bearing capacity of prefabricated concrete slabs is underestimated and additional loads are added arbitrarily, it may trigger building collapse accidents.

Inconsistent Quality: The quality of prefabricated concrete slabs on the market varies greatly, with many being of inferior quality. These low-quality slabs may be produced using substandard raw materials and non-standard manufacturing processes, resulting in strength, durability, and other performance indicators that fail to meet standard requirements, with extremely short service lives. During building use, these low-quality slabs may suddenly fail without obvious signs, triggering building collapse accidents.